1. Field of the Invention
The present invention relates to a pulse density modulation (PDM) output temperature sensor.
2. Description of the Related Arts
Currently, a temperature sensor that outputs a digital signal based on a temperature is included in a variety of electronic devices. FIG. 11 is a block diagram illustrating a conventional temperature sensor.
The conventional temperature sensor includes a reference voltage circuit 102 that generates a bandgap reference voltage VREF, a temperature detection circuit 106 that corrects a temperature dependent voltage to generate a voltage VCORR, a circuit 108 that outputs a reference voltage VHREF based on the bandgap reference voltage VREF and the voltage VCORR, a circuit 110 that multiplies the reference voltage VHREF by a factor (1/C) to output a reference voltage V0, a temperature detection circuit 104 that generates a temperature dependent voltage VTEMP, and an analog to digital converter (ADC) 112 that outputs a digital signal based on the reference voltage V0 and the temperature dependent voltage VTEMP (see, for example, U.S. Pat. No. 6,183,131).
However, the conventional temperature sensor uses the reference voltage circuit 102. Accordingly, the conventional temperature sensor requires a larger area and consumes more power correspondingly.